1. Technical Field
The present invention relates to means to provide a novel fuel burning element, such as a candle or lamp, which consumes fuel more efficiently while presenting an aesthetically pleasing appearance. The candles or lamps of the present invention comprise a solid fuel element, a consumable wick, and heat conductive means to transfer heat from the burning fuel, i.e. the flame, to the remaining fuel, thereby assuring its more rapid and complete melting and uniformity of temperature.
2. Background Art
Ordinary candles comprise a vertical, self-supporting body or column of wax, with a substantially horizontal top and a central longitudinal wick which extends through and above the wax. The exposed portion of the wick above the solid wax is lighted by a flame, and the heat generated by the lighted wick melts a small volume of the wax at the top of the candle, proximate the wick, establishing a puddle or reservoir of molten wax to serve as fuel for the flame on the wick. The capillary attraction of the molten wax and the wick, which is generally a structure of closely related fibers, causes the molten wax to travel through the wick to the flame, by which it is consumed. As the wax is consumed in this manner, the body of wax diminishes and the top surface thereof progressively lowers. The upper portion of the wick, extending above the lowering wax, is generally consumed by the flame.
Also well known are such candles or lights as tea lights, in which a body of paraffin is located in a container having a wick centrally disposed. At the lower end of the wick is a wick holder or wick clip, which functions to retain the wick in its perpendicular position, even as the paraffin is melted and liquified by the heat of the flame. In most such candles, the wick is a cotton material saturated with the paraffin, and burns with the paraffin, thus being consumable. In such candles, or lights or warmers employing the same, the visible flame diminishes as the wick is consumed, the container becomes hazardously over-heated by the flame, and the unit is time-limited by the volume of paraffin and size of the wick initially present. Further, after consumption of all of the wax in the unit, the container and the wick holder remain to be disposed of by the consumer.
Similarly, liquid fuel lamps are known in which a wick is supported with one end suspended in a reservoir of liquid fuel, such as lamp oil. By capillary action, the liquid fuel rises through the wick to the upper end thereof, where it is subjected to consumption by a flame. As fuel is consumed by the flame, additional fuel rises through the wick by capillary action to feed and maintain the flame. Permanent, or non-consumable, wicks are most frequently employed for this type of lamp.
In U.S. Pat. No. 4,557,687, Schirneker teaches a fuel element comprising a shell-like elongated housing in which a supply of fuel may be placed, with a wick immersed in the fuel supply with its upper portion protruding from the top of the housing. When the fuel is a solid fuel, such as paraffin, the wicks must conduct heat into the housing of the fuel in the area of the immersed wicks so as to provide sufficient amounts of molten paraffin to be drawn up in the wick. Such conductivity may be obtained by means of a piece of metal embedded in the wick. The purpose of the fuel element is to provide a simulated log for a fireplace which does not require a chimney.
In U.S. Pat. No. 3,741,711, Bryant teaches a composite decorative candle formed of clear, undyed and unpigmented candle wax in any appropriate candle shape, provided with a centrally recessed glass cylinder into which a replaceable small candle may be placed. Thus, the decorative outer candle may have a refill unit, such as a votive or tea light, placed therein to provide indefinite reusability. If the outer candle body comprises surface ornamentation, a luminescent glow through the candle body results when the inner candle is burned, and the outer candle is not consumed.
U.S. Pat. No. 3,910,753, of Lee, discloses a wax burner comprising a vessel having a heat conducting metal heat sink surrounding and supporting a wick which projects upwardly, and has a heat conductive metal core means conducting heat into the heat sink, which acts as a wax melting surface. The wax burner may be fueled by paraffin wax or other suitable solid fuel, which may be added to the melting surface as required. The burner may constitute one or more burner units. In Lee, however, the fuel is neither supported nor contained by the heat sink, which is configured much like a spool, with upper and lower flanges, or upper and lower flat, horizontal surfaces. The upper flange or upper surface acts as a heating surface, while the lower flange serves as a base for the heat sink, engaging the bottom surface of the burner vessel. Slots in the vertical surface of the heat sink provide means for the wax, melted by the heat sink, to flow from the exterior surface thereof to the internally located wick. Since the wick structure of the patent includes a metal core and a heat conductive metal sleeve about the wick, the wick structure is an integral portion of the heat sink of the burner assembly, and is non-consumable, and requires priming with wax prior to its first use. In use, solid wax is added to the heating surface, and replenished as necessary, or the entire vessel may be filled with wax. It is to be noted that the vessel itself is not used to conduct heat to the fuel, but only to contain it, and that a separate heat transfer system, i.e. the heat sink structure, which is independent of and distinct from the heat radiated by the flame itself, is utilized to achieve burning of the wax fuel. Even with this added heat transfer mechanism to assist in melting of the fuel, complete utilization of all of the fuel in the vessel is unachievable, even when the burner is permitted to burn to self-extinguishing, in view of the relative positioning of the lower flange and the wax conducting means of the heat sink (i.e. slots in the vertical surface thereof, above the lower flange).
In U.S. Pat. No. 2,713,256, Oesterle et al teach a votive candle having a wick extending downward in the bottom of the candle into a tapered central body projection, where said wick engages an adapter inserted into the cup for the votive. The adapter is provided with means to support the wick of the candle until the candle has completely burnt out, thereby leaving no wax or wick residue in the cup, enabling a new candle to be inserted into the cup without removal of the adapter. The adapter does not function to provide a more even or uniform burning of the candle, but to provide a proper positioning of the votive candle. When placed over the adapter, and the upwardly directed tube thereof, the flame on the wick comes into contact with a wicking material retained in the base of the tube, so as to ignite such wicking and assure that all of the melted wax is burned, thus leaving a clean cup containing no remains of the previous candle when a new candle is put in place.
European Patent Application EP 1 054 054 A1, published Nov. 22, 2000, teaches a candle having a wick clip assembly for candles to be used on a supporting surface, wherein the wick clip provides enhanced control over heat transfer form the flame to the supporting surface upon which the candle rests. In this patent, the object of the wick clip assembly is to dissipate heat from the flame away from the support surface, essentially the opposite of the goal of the present invention.
A number of additional patents teach the use of heat conductive elements to liquify solid fuel for consumption at a wick, or to dispense an element such as a fragrance or insect control material. These include U.S. Pat. Nos. 5,078,591 of Despres; 4,755,135 of Kwok; and 5,425,633 of Cole; as well as PCT Application WO 89/06141, assigned to Lamplight Farms, Inc.
None of the foregoing references, however, provide a long burning candle or lamp device capable of rapidly and completely melting a solid fuel and ensuring efficient and complete utilization of all of the fuel provided, while providing increased safety and convenient refilling. Further, the concept of the present invention offers highly decorative as well as functional candles and lamps, which may utilize a variety of gel and solid fuels, with the significant advantages of permitting rapid and convenient replacement of one fuel element by another at the whim of the consumer.
As utilized herein, the term melting plate candle shall encompass the combination of a solid fuel element, and a container or holder for the fuel. On the other hand, the terms fuel container and fuel holder shall be meant to encompass a melting plate comprising means to contain, support and melt the fuel element, a wick affixed to said melting plate, and heat conductive elements to transfer heat from a flame upon said wick to said melting plate. Thus, it may be seen that the melting plate functions to hold the fuel element, while also serving to retain the wick and to conduct heat to the solid fuel element to thereby melt said fuel to provide a liquid fuel to feed to the flame via the wick. Accordingly, the manufacturer may provide melting plate devices and solid fuel elements independently or separately, and the consumer may join the two to form a melting plate candle or fuel burner, with the option to change fuel elements at will.
The present invention provides a means for the burning of solid fuel elements, wherein said means ensures the maximum utilization of the solid fuel provided. The melting plate devices of the present invention comprise a container for gel or solid fuels, and a wick, and provide an improved transfer of heat from a heat source, a flame burning the fuel at the wick, to the remaining fuel and, more importantly, back to the container for said fuel. Such devices are preferably both functional and designed so as to be decorative or esthetically pleasing.
The melting plate candle of the present invention comprises a fuel element, a container for the fuel, which container comprises a heat conductive heat plate, or melting plate, in direct contact, and in supporting or containing relationship, with the fuel element. The melting plate candle of the present invention may further comprise heat conductive elements to transfer heat by conductive means to the fuel and to the melting plate, in addition to that heat transfer obtained by radiation from the flame. Such conductive elements result in improved transfer of heat from the burning wick to both the fuel and the melting plate, with which the fuel is in contact, thereby heating the fuel over a relatively large surface. This, in turn, provides for rapid melting of solid and gel fuels, and rapid heating of the thus melted fuels, to provide a more uniformly heated pool of fuel. Since a goal of the present invention is to more rapidly heat the fuel to temperatures which are not readily achieved by a conventional candle or lamp, so as to more fully melt the solid fuel and to improve consumption of the fuel, the heating plate element shall hereinafter be referred to as a melting plate.
The melting plate, which acts both as a fuel container and a heat transfer means to heat the fuel, is shaped so as to collect the melted or liquified fuel at its lowest point, at which point a wick is located, so as to ensure that all fuel is fed to the wick, whereby the maximum consumption of the fuel is achieved. Thus, the melting plate is preferably shaped as a bowl, or in the form of a funnel, with the lowest portion thereof preferably, but not necessarily centered. The wick is located so as to be at the lowest portion of the melting plate, and may be positioned in a complementary depression in the fuel container or melting plate. The entire interior surface of the fuel container is preferably highly heat conductive, and supports, contains, and heats the fuel, although containers in which only a small portion of the interior surface acts as a melting plate are within the scope of the present invention. The heat conductive surfaces of such containers shall be referred to as the melting plate, and candles employing such melting plates shall be referred to, collectively, as melting plate candles. In the preferred embodiments, the melting plate shall comprise the entire fuel container.
Moreover, the melting plate helps to control the shape and depth of the pool of fuel which is burned at the wick, and to maintain the constancy thereof. It is to be understood that the fuel utilized in the present invention may be initially in solid or gel form, but must be in liquid form for moving up the wick by capillary action to the flame, where it is consumed. Thus, the fuel used with the melting plate candle shall be such that it will not be transported by capillary action at ambient or room temperature, but requires heating to a liquified state, i.e. melting, to be subject to wicking action. For convenience, the term solid fuel shall be used hereinafter to refer to fuel in either a gel or conventional solid state, such as conventional candle wax. It is also to be understood that the fuel consumed in the flame at the burning wick is drawn by the wick from a liquid pool of fuel, which pool is formed by melting of the solid fuel, said liquid pool being heated by conductive heat transfer by the melting plate, the wick, and heat exchange elements, in addition to the radiant heat from the flame on the wick. By the use of the melting plate technology of the present invention, in addition to the conventional radiant heating of the surface of the fuel, the size and temperature of the liquid pool of fuel are better regulated, and as a result of greater heat transfer to the fuel, a melted, liquid pool thereof is more rapidly formed and heated to a relatively high temperature, and efficiency of consumption thereof is improved. Because the speed of achieving a liquid pool of fuel is increased, a more efficient consumption of the fuel results, as well as a more complete usage of available fuel, due to the decrease of fuel left unburned on the surface of the melting plate. In preferred embodiments of the present invention, a pool of liquid, i.e. melted, fuel rests upon the surface of the heat conductive melting plate. This pool of fuel may contain unmelted fuel in the solid state, as well as melted fuel.
Generally, the melting plate device embodies both a melting plate and a heat conductive element, which element is in close proximity to the flame, to ensure more uniform and rapid heat distribution from the flame upon the wick. The wick is affixed in its preferred position by means of crimping to a wick clip, press fit, or by other appropriate conventional means, such as by welding, soldering, or cementing, as with an adhesive. The wick may be any filamentary body which is sufficiently sturdy, which will burn with a steady flame, and which is capable of drawing up the molten candle fuel by capillary action. Such a wick may be of any conventional consumable wick material, such as cotton, cellulose, nylon, or paper. The wick may preferably be located in the center of the candle, or may be off-center as desired. The presence of two or more wicks is also within the scope of the present invention.
The heat conductive element may constitute a portion of the melting plate itself, formed or bent to be in proximity to the flame, or may be a separate assembly which is utilized in conjunction with the melting plate and consumable wick. For example, the melting plate may constitute a bowl shaped container having its outer periphery in close proximity to the flame, such as a container in which the upper lip of the bowl is formed so as to curve back toward the center of the bowl. Alternatively, the melting plate may have one or more raised portions, or lobes, which may act not only to absorb and distribute heat by conduction, but to channel or direct the flow of liquid fuel to the wick, and/or to engage the fuel element in such a manner as to properly position it. Further, the lobes may constitute areas of higher heat conductivity than surrounding areas of the container.
However, as indicated, the heat conductive element may also be a separate and independent assembly, including means to support and locate the wick, which assembly may be replaced as necessary or desired, but is preferably a permanent feature of the melting plate. The heat conductive element assembly may take the form of heat fins or heat conductive surfaces having either vertical or horizontal orientation, or elements of both. In preferred embodiments, such heat conductive elements are heated by contact with the flame, or by radiation of heat from the flame, and conduct such heat to the melting plate and to the fuel so as to more efficiently heat the fuel.
It is to be understood that the heat conductive elements may be so situated and shaped as to engage or interlock with a replaceable or refillable solid fuel element, such as being of a specific shape or configuration that will engage or mate with a complementarily shaped fuel element. In a similar fashion, the heat conductive elements and/or the fuel container may be formed in such a manner as to permit placement of fuel elements of specific configuration, such as balls, cylinders, or cubes, for example, in a preferred position in proximity to the heat conductive elements themselves, or to the wick, in such a manner as to maximize heat transfer to said fuel elements.
The present invention is thus a melting plate candle, said melting plate candle comprising, in its most basic form, a container, and a solid fuel element having a consumable wick, wherein said container is configured so as to cause the flow of liquid fuel to the wick, at which wick the fuel may be burned to produce heat so as to liquify said solid fuel element. In a preferred embodiment, the melting plate constitutes a container comprising a melting plate configured so as to cause the flow of liquid fuel to the wick, a consumable wick, and a heat conductive element to conduct heat from a flame at the wick to the melting plate, which is in contact with a solid fuel element. In such a preferred embodiment, the fuel is a solid wax, which is melted by heat conducted via the heat conductive element and the melting plate, to provide liquid fuel to the flame via the wick.
In one aspect, the invention provides a method for fueling a long-burning melting plate device, wherein replenishment fuel is added as necessary or desired, without the need to extinguish the flame while additional fuel is provided. By use of a conductive melting plate, the solid fuel is heated over a relatively large surface area, to speed the melting and heating of a large volume of solid wax or fuel. The liquid pool of wax or fuel thus formed acts both as a reservoir and a safety feature, since such a pool will act to extinguish a flame at the wick if the pool level becomes excessive, or if the device is tilted excessively, particularly as the melting plate is so configured as to cause liquid fuel to flow to the wick.
The objects of the present invention therefore include providing melting plate candles and lamps, which are:
(a) capable of burning for extended periods without close attention;
(b) capable of burning a variety of fuels which may be conveniently and rapidly changed or added as desired;
(c) able to rapidly produce a pool of melted wax for consumption at the wick;
(d) highly decorative;
(h) self cleansing, in the sense that they leave little or no residue of unburned fuels; and
(i) relatively inexpensive to produce, and economical for the consumer.
The use of the melting plate technology of the present invention may also provide such advantages as elimination of tunneling, significant reduction of retention of wax at the conclusion of the burn, elimination of walking or off-center wicks, while also giving a large pool of liquid wax with a relatively small flame in a relatively short time period. In addition, the container may be of almost any shape desired, providing for great aesthetic possibilities. Since the fuel element is provided as a separate unit, the consumer may be provided a great number of choices as to the color and nature of the fuel, and the configuration of the fuel element may be varied to provide a large choice of shapes, such as seasonably decorative items. For example, shapes such as pumpkins may be provided for Halloween, and wreaths for Christmas. In addition, the fuel element may be so configured as to cooperatively engage the melting plate and/or the heat conductive element, in such a manner as to provide the consumer the greatest degree of ease in placement of the fuel element in optimal position in the melting plate candle, with the least possibility of incorrect placement.
Thus, an object of the present invention is to provide a lamp or candle device, said device comprising, in combination, a fuel element comprising a solid fuel, a container for said fuel element, and, a wick at which said fuel may be burned to produce heat so as to melt said solid fuel, wherein said container is configured so as to cause the flow of melted fuel to said wick.
Accordingly, it is an object of the present invention to provide a melting plate candle, wherein said candle comprises a container for a fuel element comprising a fuel selected from the group consisting of paraffin, beeswax, montan wax, carnauba wax, microcrystalline wax, stearic acid, fatty alcohols, fatty acids, fatty esters, and gels incorporating such fuels, in a form selected from the group consisting of pucks, donuts, chips, slivers, balls, pellets, shavings, particulates, cubes, discs, three dimensional shapes, and wafers, or in any other suitable shape, wherein said container is a concave melting plate further comprising a consumable wick and a heat conductive element chosen from the group consisting of lobes, fins, wick holders, and combinations thereof, and said heat conductive element cooperatively engages said fuel element.
Similarly, a further object of the present invention is to provide a melting plate candle or lamp, said candle comprising, in combination, a meltable solid fuel, a consumable wick, a conductive base upon which said fuel rests, and heat conductive elements by which heat is conducted to said base from a flame upon said wick, whereby a pool of heated liquid fuel is created, wherein said heat conductive base is configured so as to cause the flow of said heated liquid fuel to said wick for combustion, and said base and said elements are configured so as to cooperatively engage said fuel.
Accordingly, an object of the present invention includes providing a melting plate candle comprising a solid or gel fuel, which fuel is melted by a heat conductive element selected from lobes, fins, wick holders, or combinations thereof, said heat conductive element being heated by a flame at a wick, a heat conductive base upon which the fuel rests, the base being configured so as to cause the flow of melted fuel to the wick, and the heat conductive element configured to cooperatively engage the fuel element.
A further object is to provide a melting plate lamp or candle comprising a replaceable fuel element, and a fuel containing device comprising a heat conductive melting plate, a wick, and a heat conductive element to collect heat from a flame at said wick and conduct said heat to said melting plate to thereby melt said fuel and form a pool of liquid fuel on the surface of said melting plate, wherein said containing device is configured to position and engage said fuel on said melting plate for rapid melting, and said melting plate is shaped so as to cause said pool of liquid fuel to flow to said wick.
Also desired is a solid replacement element for a lamp or candle, said element comprising a solid fuel having a consumable wick element. Applicants further teach a device comprising a heat conductive container having affixed thereto a wick, said container configured so as to cause the flow of liquid contents to the wick and to engage and melt a solid fuel element.
These and still other objects and advantages of the present invention will be apparent from the description which follows. The following description is merely of the preferred embodiments, and the claims should be looked to in order to understand the full scope of the invention.